Hand held tube bending tool



April 22, 1958 c. E. KLAMM HAND HELD TUBE BENDING ToL Filed Dec. 18,1953 INVENTOR Z JL Za mm Cari ( ATTORNEYS HAND HELD TUBE BENDING TooLCarl E. Klamm, Cleveland, Ohio, assignor to Parker- HannifinCorporation, a corporation of Ohio Application December 18, 1953, SerialNo. 399,059

Claims. (Cl. 81-15) The invention relates generally to tube bending andprimarily seeks to provide a novel inexpensive and yet efiicient handtool for this purpose.

Hand held and actuated tube benders are, of course, known, but presentlyknown tools of this character leave much to be desired because of beingcomplicated in structure and cumbersome, and because in most instancesthey have no provision for quick insertion or removal of the tubingwithout endwise threading thereof through receiving openings or completeremoval of parts. It is a purpose of the present invention to provide animproved hand tool of the character stated which will eliminate thedisadvantages referred to.

In its more detailed nature, the invention resides in providing a handtool of the character stated including a handle, a radius block or benddefining die fixed on the handle and having a periphery extending aboutapproximately three-fourths of a complete circle and a tube contactingand bend defining groove therein, a link swingable about the die andhaving a bending die pivoted to the free end thereof for following aboutthe periphery of the fixed die, and an open hook disposed to receive andhold a tube portion in tangential relation to the bend defining groovewhile the swingable die is swung about to bend the tube, one groovedefining side wall of the fixed die being removed to provide anangularly disposed clearance adjacent the hook effective to receive atube into the hook and between the fixed and swingable dies withoutnecessity of endwise threading the tube.

Another object of the invention is to provide a hand tool of thecharacter stated wherein the tube holding hook is shaped to embraceapproximately one-half the circumference of a tube cross section.

Another object of the invention is to provide a hand tool of thecharacter stated wherein the tube holding hook is secured againstmovement relative to the fixed die.

Another object of the invention is to provide a hand tool of thecharacter stated wherein the fixed die has a scale extending from zerothrough one hundred and eighty degrees about the periphery thereof, thefixed handle extending perpendicularly with relation to a linetraversing said die and passing through the zero and one hundred eightydegree marks on the scale, the hook being disposed to parallel saidline, and the groove defining wall cut away being disposed inapproximately fortyfive degree angular relation to said line starting atthe zero mark and extending toward said hook.

Another object of the invention is to provide a hand tool of thecharacter stated wherein the swingable die has a stop lug thereonengageable with the link end to which said die is pivoted to place thetube engaging surface of said die in tangential relation to theperiphery of the fixed die.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following 2,831,382 Patented Apr. 22, 1958 detailed description,the appended claims and the several views illustrated in theaccompanying drawing.

In the drawing:

Figure 1 is a face view of the tool, the handle carrying the swingabledie being swung to the tube receiving position in full lines, and to theposition for completing a bend in dotted lines.

Figure 2 is an end view with the parts at the bend completion positionshown in dotted lines in Figure 1.

Figure 3 is a vertical cross section taken on the line 3-3 on Figure 1with the swingable die in the bend completion position shown in Figure2.

Figure 4 is a detail perspective view of the movable die.

Figure 5 is a detail perspective view of the fixed die.

Figure 6 is a detail perspective view of the tube holding book.

In the practical development of the invention, the improved hand tool isformed to include a radius block or bend defining die 5 fixed in anyapproved manner to a handle 6. The die 5 has a periphery 7 extendingabout approximately three-fourths of a circle, and the handle 6 projectsradially with relation to said periphery, or in perpendicular relationto the flat or chordal face 8 of the die.

A scale 9 extends about the periphery of the die 5, extending over 180from a zero mark to an 180 mark, the scale being so placed that animaginary line drawn through the zero mark and the 180 mark willparallel the flat or chordal face 8 of the die. The peripheral surfaceof the die is provided with a tube engaging bend defining groove 10which is approximately half circular in radial cross section, and itwill be noted that one side wall defining said groove is cut away at a45 angle as at 11 to provide for free entrance of a tube to be bent. Itwill be noted that the cut away 11 starts at the zero mark of the scaleand extends to the flat face 8 of the die 5 which is opposed by a tubesecuring hook 12. The hook is secured in any approved manner between thedie face 8 and the adjacent end of the handle 6, and has a tubereceiving seat 13 which is shaped to extend about at least half thediameter of a tube held thereby. It is to be noted that the hook end isinturned into the groove of the die 5 as at 14 so as to be securedagainst swinging movement about the axis of the handle 6'. In otherwords the book 12 is fixed with relation to the handle 6 and the radiusblock or bend defining die 5 carried thereby.

A link 15 is pivoted on the axis of the die 5 at one face thereof as at16, and a handle 17 is swingably mounted on'the free end of the link asat 18'. The handle 17 includes a part circular portion 19 at the pivotalmounting thereof, and also a die portion 20 having a half-round groove21 therein. The groove 21 is formed in a face 22 of the die portion 20so placed as to oppose the periphery of the die 5 slightly out ofcontact therewith and in tangential relation as the'handle 17 and link15 are swung about the die 5 on the pivotal mounting 16' with the link15 and arm 17 in the angular relation shown in dotted lines in Figure 1and held in such relation by the stop lug 23 projecting from the camportion 20 in position for contacting the link 15.

In the use of the tool, the arm 17 is swung into the full line positionillustrated in Figure 1, and in this position a tube to be bentindicated at 24 can be inserted in the die clearance 11 as indicated indot and dash lines in Figure 1, and then turned into the hook seat 13and the groove 10 of the die 5, or in other words parallel to the handle6. With the tube inthis position, and held by the hook seat 13, thehandle 17 will next be swung to present its die face 22 in tangentialrelation to the periphery of the die 5 so that the groove 21 thereinwill cooperate with the groove 10 in the die 5 in completely encirclingthe tube. This swinging of the handle to present its die face 22 intangential relation to the periphery of the die 5 will bring the stoplug 23 against the link 15, and thereafter the handle 17 and link 15will swing in unison about the pivotal mounting 16, bending the tube tothe position illustrated in dotted lines in Figure 1, assuming that a180 bend is desired.

It will be apparent that tube bends of various degrees can be made, andthe tube can be quickly mounted and dismounted by lateral insertion ofintermediate portions thereof between the die clearance 11 and the hook12, without any necessity of endwise threading the tube or the removingof any parts. It will also be apparent that swinging movement of thehook 12 is unnecessary and, in fact, is impossible.

While one form of the invention has been shown for purposes ofillustration, it is to be clearly understood that various changes in thedetails of construction and arrangement of parts may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

I claim:

1. A hand tool of the character described comprising, a handle, a benddefining die fixed on the handle and having a periphery extendingapproximately about threefourths of a complete circle and a tubecontacting and bend defining groove therein, a link swingable about thebend defining die on a fixed pivot, a bending die pivoted to the freeend of the'link in position for following about the periphery of thefixed bend defining die as the link is swung on its pivot, a handleextending from the swingable bending die for placing the swingablebending die and swinging it with the link, and an open hook fixed as toposition with relation to said fixed bend defining die and the groovetherein and disposed to receive and hold a tube portion in tangentialrelation to the bend defining groove while the swingable bending die isswung about to bend the tube, one groove defining side wall of the fixedbend defining die being removed in part to pro- I vide an angularlydisposed clearance adjacent the hook effective to receive a tube intothe hook and between the fixed and swingable dies without necessity ofendwise threading of the tube.

2. A tool as defined in claim 1 wherein the hook is shaped to present atube opposing clearance in the plane of the fixed bending die groove andshaped to embrace approximately one half the diameter of a tube heldthereby during a bending operation.

3. A tool as defined in claim 1 wherein a portion of the hook isindented into a portion of the fixed die so as to be secure againstmovement relative to said die.

4. A tool as defined in claim 1 wherein the fixed die includes a flatface comprising a chord of the periphery circle, the fixed die handleprojecting perpendicularly with relation to said chordal face, the hooklying parallel to said face, and the groove defining Wall cut away beingdisposed in approximately forty-five degree angular relation to saidhook and ending directly against said hook.

5. A tool as defined in claim 1 wherein the hook is shaped to embraceapproximately one-half the diameter of a tube held thereby during abending operation, it being provided with a substantially half tubediameter tube embracing clearance directly opposed to the handle axis inthe plane of the bend defining die groove and merging with the remainderof the hook through a curving clearance disposed opposite and openinginto the angularly disposed clearance in said bend defining die.

References Cited in the file of this patent UNITED STATES PATENTS1,659,026 Henderson Feb. 14, 1928 1,835,264 Blythe Dec. 8, 19312,127,185 Parker Aug. 16, 1938 2,428,237 McIntosh Sept. 30, 19472,678,573 Taylor May 18, 1954 FOREIGN PATENTS 417,656 Great Britain Oct.3, 1934

